Ultrasound imaging systems generate ultrasonic echoes from deliberately launched diagnostic sound waves into tissue. The ultrasonic echoes are attenuated in proportion to the distance that the sound waves must travel to reach the reflector, plus the distance that the resulting echoes must travel back to reach the receiver. The ultrasound echoes are displayed on a screen, providing medical information for the operator.
All diagnostic ultrasonic imaging systems employ some type of acoustic power control. In general, the control of acoustic output levels are based on fixed pre-determined schemes. There are a number different parameters that directly or indirectly control the acoustic output power levels of an diagnostic ultrasonic imaging system. Numerous systems constraints affect control of the acoustic output power levels, including hardware limitations, transducer temperature limitations, and regulatory allowable dose limits. Since the control of acoustic output levels are based on fixed predetermined schemes, and numerous constraints exist, acoustic power control poses a difficult problem in diagnostic ultrasonic imaging systems.
It would be desirable then to have an acoustic power control technique which overcomes the problems associated with the prior art. The invention discussed here allows optimal dose limits to be achieved in real-time.